Penn State University researcher James Connor, PhD, led a team that autopsied the brains of seven deceased people with restless leg syndrome. The findings: Nothing was wrong with the brains themselves.

That's good news. Some experts had feared that the syndrome might mean some kind of Alzheimer's-like degenerative disease. What Connor's team found was a problem with brain cells in a specific part of the middle brain known as the substantia nigra.

All brain cells need iron. They get it from transport molecules that carry iron from the blood. Normal brain cells have doorways that let these transporters into the cell. Patients with restless leg syndrome lacked these portals, known as transferrin receptors.

"We hope these discoveries lead to a test that could diagnose this syndrome," Connor says in a news release. He hopes the findings provide the basis for new treatments.

People with restless leg syndrome, or RLS, have a creepy-crawly feeling in their legs. This causes an irresistible urge to move the legs. It's a major cause of sleep loss, as the symptoms are most likely to occur at night.

Connor warns that the findings don't mean people with RLS need iron supplements.

"This doesn't necessarily mean that a person has a dietary iron deficiency and needs supplements," he says. "It means only that these receptors aren't packaging and delivering an adequate amount of iron to the specific cells in this portion of the brain."

Connor reported the findings at the recent annual meeting of the Association of Professional Sleep Societies in Chicago.